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Re: Index Compression question - afterquestion

From: Andy <andy.spaven_at_eps-hq.co.uk>
Date: Mon, 20 Jan 2003 08:36:52 -0000
Message-ID: <4uOW9.3530$9R.12191378@newsr2.u-net.net>


Jan

Not OS swapping - the move from non compressed to compressed indexes - if you'd done ALTER INDEX ... REBUILD COMPRESS COMPUTE STATISTICS NOLOGGING things might have been okay. Without the COMPUTE STATISTICS keywords I think you loose the statistics already gathered (much like dropping and recreating an index). Someone correct me if I'm wrong on this point.

Andy

"Jan Gelbrich" <j_gelbrich_at_westfalen-blatt.de> wrote in message news:b0bkqt$o4r2s$1_at_ID-152732.news.dfncis.de...
> Hi, Andy ...
>
> "Andy" <andy.spaven_at_eps-hq.co.uk> schrieb im Newsbeitrag
> news:mlVV9.3528$9R.12113872_at_newsr2.u-net.net...
> > Jan
> >
> > I suspect that your stats were up to date but that the process of
swapping
> > to compressed destroyed them.
>
> please excuse me, I am not sysad,
> could You be so kind to explain
> how OS swapping can destroy statistics in the data dactionary ?
>
> > Did you drop and recreate the indexes or
> > rebuild them ? If you rebuilt them did you specify compute statistics
> > clause otherwise you loose stats (I believe) ?
> >
> > Andy
> >
>
> This is what I did:
>
> ALTER INDEX ...
> REBUILD
> (no)compress --depends on the index
> nologging
> /
>
> And I always use COMPUTE to fresh up statistics
> using ANALYZE or DBMS_UTILITY.
>
> P.S. As Daniel mentioned, I should use DBMS_STATS instead ...
>
> Jan
>
>
>
Received on Mon Jan 20 2003 - 02:36:52 CST

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